GSoC Week 11: Practical Use

You know what makes code of a software library even better? Client code that makes it do stuff! I present to you xmpp_sync!

Xmpp_sync is a small command line tool which allows you to sync file from one devices to one or more other devices via XMPP. It works a little bit like you might now it from eg. owncloud or nextcloud. Just drop the files into one folder and they automagically appear on your other devices. At the moment it works only unidirectional, so files get synchronized in one direction, but not in the other.

The program has to modes; master mode and slave mode. In general, a client started in master mode will send files to all clients started in slave mode. So lets say we want to mirror contents from one directory to another. We start the client on our master machine and give it a path to the directory we want to monitor. On the other machines we start the client in slave mode, and then add them to the master client. Whenever we now drop a file into the directory, it will automatically be sent to all registered slaves via Jingle File Transfer. Files do also get send when they get modified by the user. I registered a FileWatcher in order to get notified of such events. For this purpose I got in touch with java NIO again.

Currently the transmission is made unencrypted (as described in XEP-0234), but I plan to also utilize my Jingle Encrypted Transports (JET) code/spec to send the files OMEMO encrypted in the future. My plan for the long run is to further improve JET, so that it might get implemented by other clients.

Besides that I found the configuration error in my ejabberd configuration which prevented my Socks5 proxy from working. The server was listening at 127.0.0.1 by default, so the port was not reachable from the outside world. Now I can finally test on my own server 😀

I also tested my code against Gajims implementation and found some more mistakes I made, which are now fixed. The Jingle InBandBytestream Transport is sort of working, but there are some more smaller things I need to change.